Matrix-sheet and method of producing same.



E. R. BULLARD.

MATRIX SHEET AND METHOD 0F PRODUGING SAME.

APPLwATloN FILED 1mb-.4, w11.

1,112,356, Patented sept. 29. 1914.

I NVENTUQ WITNES'EE:

f ED STATES PATENTQFF'ICE.

EDGAR R. BULLARI), WHEELING, WEST VIRGINIA, ASSIGNOR 0F ONE-HALF TO LESLIE E. MORNINGSTAR, 0F WHEELING, WEST VIRGINIA.

MATRIX-SHEET AND METHOD 0F PRODUCING SAME.

Specification of Letters Patent.

Application led December 4, 1911. Serial No. 663,899.

sketches, drawings, and the like may be,

initially .drawn or applied and which may be employed as a matrix in the process of stereotyping.

A further object is to provide a drawing or sketching sheet of the character mentioned whose face is indented with myriads of minute pits, more or less regularly formed and spaced apart, between which pits are` minute unindented portions, or undisturbed surface or relief elevations, a stipplcd or screen-like face being thus formed which negatively corresponds to the face of a half-tone plate.

A still further object is to provide a card or plate of which the aforementioned stippled sheet forms the face wherein are provided multitudes of inclosed air pockets which readily yield or break down under the pressure of a pencil, stylus, or type, allowing the material of said sheet t0 be depressed by such instruments to or below the level. of the pits therein without disturbing the adjacent relie-f portions of the field constituted by the sheet. And a still further object within the contemplation of this invention is to structurally improve and render more etlicient that character of matrix sheets exempliied in VUnited States Letters Patent to Morningstar, No. 891,499, dated June Q3, 1908. f

With these and other objects '1nv View,

- this invention resides in the features of con- Patented Sept. 29, 1914.-

lar ed, of a portion of a card or board embo ying the invention, the letter P being shown impressed thereon to represent a heavy pencil line; Fig. 2 is a transverse section of an unlined portion of the stippled sheet, unmounted, still further enlarged; and Fig. 8 is asimilar section of the invention taken on the line 3 3, Fig. 1.-

Referring to said drawings, in which like designating characters distinguish like parts throughout the several views 1 indicates generally ay sheet of material, preferably of a high grade bond paper of about 20-pound folio, which is substantially covered with extremely minute indentations or pits 2 of pyramidal or cone shape produced by appropriate means, as, preferably, by a metal plate or roll applied under pressure to the sheet, the face of said plate or roll having myriads of minute projections which are preferably regularly shaped and spaced. The sheet is thus embossed, presenting al ternate elevated or relief ridges or lines 3 and indentations or pits 2.

The sheet 1 is firmly mounted, after being embossed, upon a base or backing`4 of suitable material, which, while having a surface that is slightly yieldable under pressure, is relatively firm and sti, the Inaterial preferably employed for such base or backing being a cardboard blank of about 8-ply. A suitable cement or adhesive slibstance 5 is employed as a mountant, a thin coating or film thereof being ap-plied to the base or backing, after which the matrix sheet 1 is placed thereon and. is pressed or rolled for causing` the downwardly directed apices 6 of the sheet to sink into, or become embedded in, the adhesive substance, as shown in Fig. 3. Inclosed air spaces or pockets 7 are formed between the mountant and the inclined walls defining the pits or indentations 2, there being thus constitute-dv innumerable minute pneumatic cushions which are readily sensitive to the pressure of the artists pencil. When the pockets 7 become partially or` entirely filled with the adhesive substance, as sometimes happens, when, through carelessness, ithas aoA vthe stereotype, which is produced therei as above described, is, as will be readily understood, soft and yielding, and is readily depressed by the point of a pencil, stylus, yor other drawing or sketching instrument, or by the face of type, or cuts, `to the level of the pit-formed apices 6.

In practice, slightly more than the slight pressure required to break down or depress the relief surface or lines 3 and the walls delinmg the pits is preferably applied in order that the point of the pencil or other instrument may depress the material to or slightly below7 the level of the upper surface of the base or backing 4, thus forming 1n the matrix a clearly defined line or depression, as shown at S. The points or indentations in the face of the matrix sheet are of substantially uniform depth and are extremely small and close together, there being about sixty-nine to the inch. Hence,

fromby pouring molten metal thereover, as 1n casting from a matrix in the ordinary or usual manner, has practically the same -uniform` screenflikelines or dots for proj ducing the well known sti-ppled andlined effect of a half-tone out. Drawings, picltures and the like for reproduction, as for newspaper and magazine cuts, may be readily made directly upon the face of the matrix sheet, the surface not being roughened by the alternate pits or indentations and relief elevations to such an extent as will retard or appreciably interfere ywith the movement of the point of the drawing Yor* sketching instrument thereover. The drawing may be made directly upon the matrix sheet, or may be applied thereto by tracing, as by means of an interposed carbon sheet, or in any other manner by which the lines of the drawing may be impressed in the sheet.' It will be understood that when a sheet of paper, as a good quality of turbing action-that is, without filling in or changing the indentations v; or surfaces adjacent to the artists lines-of depression.

Having thus described my invention, what I claim as new, and desire to secure by'Letters Patent, isl. A matrix sheet comprising a thin sheet of readily impressionablematerial which is embossed by indentations extending therethrough to present a working surface havling alternate minute stipples in depression :and relief lines, said sheet having its `reverse face cemented to a base of relatively firmer material having a yieldable surface in such manner that minute air pockets are vconstituted between said base and therelief. elevations, whereby a pliant working surface 1is'provided whereon lines may be impressed without disturbing adjacent lines .or stip les.

2. T e herein described method of forming a matrix sheet, which consists, first, in embossing a sheet of fibrous tissue to produce on its working face a field of minute stipples in depressiony and interposed relief lines in elevation, second, in mounting the reverse face of said sheet upon a base of a relatively firmer yieldable material so V/that air-containing pockets are formed between said base and the walls defining said relief lines, and then depressing some of the elevated lines to or below the level of .the stipples to form in said 'sheet a desired design.

3. The herein described method of formling a matrix sheet, which consists, first, in embossing through a sheet of thin paper to produce on its working face a field of minute substantially conical stipples in depression and interposed relief lines, second, in mounting said embossed sheet upon a relatively heavier and firmer base so that only the apices of the stipples enga e said base and so that air-containing poc ets are formed between said base and the walls defining the relief lines, and then breaking down portions of said relief lines to produce a desired design in depression on said working face of the embossed sheet.

' In testimony whereof I affix my signature in presence of two subscribing witnesses.

EDGAR R. BULLARD. Witnesses:

F. L. KROHE,

H. E. DUNLAP. 

